goby
Premium Member
so, I finally got around to upgrading my 1990s spectrapure 4 stage recently.. It was in a bad state, so i splurged and bought a few upgrades while I was buying the replacement cartridges and a new membrane..
the end result is a 5 stage chloromines setup that I am quite happy with, but it has left me with more questions than answers..
I added a single canister in the front, and use that as the prefilter, then to a Catalytic Carbon (BRS refillable thing) cart, then to the Pentek? chloromines cart. After that, I hit a TDS meter and a pressure guage before going on to the membrane. After the membrane is a TDS meter before the DI, and another TDS after the DI.
I replaced the stock flow restrictor with one of those ballvalve flush kit/flow restrictor combos. It's the 550ml one recomended for a 75gpd membrane for higher rejection ratio than the 400ml.
oh, its a Dow filmtec 75 gpd membrane.
ok, now the numbers that lead to the questions:
TDS in (from tap with a handheld meter) = 125
TDS after pre/carbons = 300
TDS after membrane = 7
TDS after DI = 0
pressure before membrane = 50psi
Waste/product ratio = 2:1
5 gallon production time : 1hr 20 mins.
5 gallon waste production time : 40 mins.
I built the unit up and have made at least 10-15 gallons of product water at this point.
Questions:
Do the carbon filters really add that much TDS before hitting the membrane? seems like it might be worth it to add a .5 micron sediment AFTER the carbons to extend the life of the membrane, no?
Why is my waste/product ratio only 2:1?? I thought this should be closer to 4:1 and I bought the flow restrictor/flush valve (550ml) that is supposed to reject MORE than the 400ml.
I bought the BRS kit for the refils, and I tried to add ALL The carbon and DI Resin to my cartridges, but it didnt fit.. I shook/tapped to make sure they were packed full, but neither took ALL the media. is this normal? I would say i have about 1/4 cup of each left over..
I did add a carbon fines flush after the CAC cartridge, and when I first ran the unit, I had it hitting the CAC and then dumping right there, not hitting the rest of the carts, but I saw no discolored water at all.. Ran a good gallon thru it, then flipped the valves to run throught the rest of the system, and all seems ok? at first the TDS at the membrane was 400, and its settled to 300, so is that normal? to not get much fines from the carbon? or could i have packed that cartridge too tight? I Figured not, I didnt think I could pack it tighter than a 1micron carbron block...
The DI canister never fills with water. I Belive this is due to a lower pressure situation after the membrane. as it was full of air, and the water "falls" thru the air to the bottom and goes thru the cartridge, I assume this is ok, is it?? Should i just fill the canister wtih water before i screw it back on? would a Permeate pump work here? to increase pressure to the DI caninster? or not needed?
Would a premeate pump raise my pressure at the membrane by much? at 50psi I am kinda on the low end, and thinking raising that may help with the waste water production rate. ideas?
The product water tastes a bit "funny". I think its tastes similar to how the DI resin smells, I assume this is going to go away after I process many more gallons thru the unit? I dont recall having this issue when I have used premade carts in the past.
ok, sorry to ramble on with probably non-issues, but just getting back into the hobby after many years on "Cruise control" and feeling like a newb again full of questions
the end result is a 5 stage chloromines setup that I am quite happy with, but it has left me with more questions than answers..
I added a single canister in the front, and use that as the prefilter, then to a Catalytic Carbon (BRS refillable thing) cart, then to the Pentek? chloromines cart. After that, I hit a TDS meter and a pressure guage before going on to the membrane. After the membrane is a TDS meter before the DI, and another TDS after the DI.
I replaced the stock flow restrictor with one of those ballvalve flush kit/flow restrictor combos. It's the 550ml one recomended for a 75gpd membrane for higher rejection ratio than the 400ml.
oh, its a Dow filmtec 75 gpd membrane.
ok, now the numbers that lead to the questions:
TDS in (from tap with a handheld meter) = 125
TDS after pre/carbons = 300
TDS after membrane = 7
TDS after DI = 0
pressure before membrane = 50psi
Waste/product ratio = 2:1
5 gallon production time : 1hr 20 mins.
5 gallon waste production time : 40 mins.
I built the unit up and have made at least 10-15 gallons of product water at this point.
Questions:
Do the carbon filters really add that much TDS before hitting the membrane? seems like it might be worth it to add a .5 micron sediment AFTER the carbons to extend the life of the membrane, no?
Why is my waste/product ratio only 2:1?? I thought this should be closer to 4:1 and I bought the flow restrictor/flush valve (550ml) that is supposed to reject MORE than the 400ml.
I bought the BRS kit for the refils, and I tried to add ALL The carbon and DI Resin to my cartridges, but it didnt fit.. I shook/tapped to make sure they were packed full, but neither took ALL the media. is this normal? I would say i have about 1/4 cup of each left over..
I did add a carbon fines flush after the CAC cartridge, and when I first ran the unit, I had it hitting the CAC and then dumping right there, not hitting the rest of the carts, but I saw no discolored water at all.. Ran a good gallon thru it, then flipped the valves to run throught the rest of the system, and all seems ok? at first the TDS at the membrane was 400, and its settled to 300, so is that normal? to not get much fines from the carbon? or could i have packed that cartridge too tight? I Figured not, I didnt think I could pack it tighter than a 1micron carbron block...
The DI canister never fills with water. I Belive this is due to a lower pressure situation after the membrane. as it was full of air, and the water "falls" thru the air to the bottom and goes thru the cartridge, I assume this is ok, is it?? Should i just fill the canister wtih water before i screw it back on? would a Permeate pump work here? to increase pressure to the DI caninster? or not needed?
Would a premeate pump raise my pressure at the membrane by much? at 50psi I am kinda on the low end, and thinking raising that may help with the waste water production rate. ideas?
The product water tastes a bit "funny". I think its tastes similar to how the DI resin smells, I assume this is going to go away after I process many more gallons thru the unit? I dont recall having this issue when I have used premade carts in the past.
ok, sorry to ramble on with probably non-issues, but just getting back into the hobby after many years on "Cruise control" and feeling like a newb again full of questions
